Copper oxide nanoparticles (CuO NPs) have severe nano-toxic effects on organisms. Limited data is available on influence of CuO NPs on plant cells. Here, the molecular mechanisms involved in the toxicity of CuO NPs are studied. Exposure to CuO NPs significantly increased copper content in roots (0.062-0.325 mg/g FW), but CuO NPs translocation rates from root to shoot were low (1.1-2.8%). Presented data were significant at p < 0.05 compared to control. CuO NPs inhibited longitudinal growth and promoted transverse growth in root tip cells. However, CuO NPs did not affect the leaf cells, implying that the transfer ability of CuO NPs was weak, and toxicity mainly affected roots. CuO NPs can conjugate with actin protein. The actin cytoskeleton experienced reorganization in the presence of CuO NPs. The longitudinal filamentous actin (F-actin) decreased, and the transverse F-actin increased. CuO NPs inhibited actin polymerization and promoted depolymerization. The behavior of individual F-actin was at steady state with time-lapse under CuO NPs treatment by time-lapse reflection fluorescence (TIRF) microscopy. The growth rate of actin filaments was weakened by CuO NPs. CuO NPs disturbed the subcellular localization of PINs and the gradient of auxin distribution in root tips in an actin-dependent manner. In conclusion, CuO NPs conjugated with actin and disturbed F-actin dynamics, triggering abnormal cell growth in the root tip, and findings provide theoretical basis for further study nano-toxicity in plants.

中文翻译：

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氧化铜纳米颗粒通过干扰拟南芥根中的肌动蛋白细胞骨架动力学来改变细胞形态。

氧化铜纳米颗粒（CuO NPs）对生物具有严重的纳米毒性作用。关于CuO NP对植物细胞影响的数据有限。在这里，研究了涉及CuO NPs毒性的分子机制。暴露于CuO NPs会显着增加根部的铜含量（0.062-0.325 mg / g FW），但CuO NPs从根部到芽的​​转运率很低（1.1-2.8％）。与对照组相比，呈现的数据在p <0.05时具有显着性。CuO NPs抑制根尖细胞的纵向生长并促进其横向生长。然而，CuO NPs不会影响叶细胞，这表明CuO NPs的转移能力很弱，并且毒性主要影响根系。CuO NP可与肌动蛋白结合。肌动蛋白的细胞骨架在CuO NPs的存在下经历了重组。纵向丝状肌动蛋白（F-肌动蛋白）减少，而横向F-肌动蛋白增加。CuO NPs抑制肌动蛋白聚合并促进解聚。通过延时反射荧光（TIRF）显微镜观察，在CuO NPs处理下，单个F-肌动蛋白的行为随时间推移处于稳定状态。肌动蛋白丝的生长速率被CuO NPs削弱。CuO NPs以肌动蛋白依赖性方式干扰PIN的亚细胞定位和根尖中生长素分布的梯度。总之，CuO NPs与肌动蛋白缀合并破坏了F-肌动蛋白的动力学，触发了根尖中异常细胞的生长，其发现为进一步研究植物的纳米毒性提供了理论基础。通过延时反射荧光（TIRF）显微镜观察，在CuO NPs处理下，单个F-肌动蛋白的行为随时间推移处于稳定状态。肌动蛋白丝的生长速率被CuO NPs削弱。CuO NPs以肌动蛋白依赖性方式干扰PIN的亚细胞定位和根尖中生长素分布的梯度。总之，CuO NPs与肌动蛋白缀合并破坏了F-肌动蛋白的动力学，触发了根尖中异常细胞的生长，其发现为进一步研究植物的纳米毒性提供了理论基础。通过延时反射荧光（TIRF）显微镜观察，在CuO NPs处理下，单个F-肌动蛋白的行为随时间推移处于稳定状态。肌动蛋白丝的生长速率被CuO NPs削弱。CuO NPs以肌动蛋白依赖性方式干扰PIN的亚细胞定位和根尖中生长素分布的梯度。总之，CuO NPs与肌动蛋白缀合并破坏了F-肌动蛋白的动力学，触发了根尖中异常细胞的生长，其发现为进一步研究植物的纳米毒性提供了理论基础。CuO NPs以肌动蛋白依赖性方式干扰PIN的亚细胞定位和根尖中生长素分布的梯度。总之，CuO NPs与肌动蛋白缀合并破坏了F-肌动蛋白的动力学，触发了根尖中异常细胞的生长，其发现为进一步研究植物的纳米毒性提供了理论基础。CuO NPs以肌动蛋白依赖性方式干扰PIN的亚细胞定位和根尖中生长素分布的梯度。总之，CuO NPs与肌动蛋白缀合并破坏了F-肌动蛋白的动力学，触发了根尖中异常细胞的生长，其发现为进一步研究植物的纳米毒性提供了理论基础。